Variation in minerals, polyphenolics and antioxidant activity of pulp, seed and almond of different ziziphus species grown in Morocco

Abstract

Vegetables from the genus Ziziphus (Rhamnaceae) have been identified as one of the main dietary antioxidants, especially phenolic compounds. However, their chemical composition varies according to the specie or the part of the plant. Mineral composition (potassium, magnesium, calcium, sodium, iron, and zinc), polyphenolic content (Flavan-3-ol, Proanthocyanidin, total polyphenol content) and antioxidant capacity (DPPH, ABTS, and ORAC Assay) in four different matrices (whole fruit, pulp, seed and almond) of Ziziphus (Z. Lotus and Z. Spina Christi) commonly grown in Morocco were investigated. As a result, minerals, polyphenolic contents and antioxidant capacity fluctuated significantly (p ≤ 0.05) between different matrices and Ziziphus species analyzed. Seeds displayed a significantly higher mineral level, polyphenolic content and antioxidant capacity in comparison to whole fruit, pulp and almond. Among species, Z. spina-christi have a significantly higher content of mineral, phenolics and antioxidant activity. These results suggest that the mineral level, polyphenolic content and antioxidant capacity vary considerably depending on the Ziziphus species and part of the plant analyzed. Furthermore, Z. spina-christi seeds presented properties desirable for use in functional food.